A nationwide warning about al-Qa'ida threats to small aircraft has been issued by the FBI and US Homeland Security, in the run-up to the anniversary of the 9/11 terrorist attacks. They say there is no specific orcredible terrorist threat for the 10-year anniversary of the attacks on the World Trade Center and Pentagon, but have stepped up national security as a precaution. A five-page law enforcement bulletin issued on Friday said that al-Qa'ida was considering ways to attack aircraft as recently as early this year. AP